The Arctic Cat T660 Turbo was a bold step for the snowmobile manufacturer, offering a smooth, four-stroke engine with forced induction in a market often dominated by two-stroke engines. While renowned for its comfortable ride and impressive power delivery, the T660 Turbo wasn't without its quirks. Many owners have encountered issues that, while not necessarily deal-breakers, are worth understanding if you own, or are considering purchasing, one of these sleds. This article dives into the common problems faced by Arctic Cat T660 Turbo owners, helping you diagnose, troubleshoot, and potentially prevent these issues.

Decoding the T660 Turbo's Appeal (and its Challenges)

The T660 Turbo was a game changer, offering a refined alternative to the sometimes-unpredictable nature of two-stroke engines. The four-stroke engine provided a linear power band, making it a joy to ride on long trails. The turbocharger added a significant boost in performance, especially at higher altitudes. However, this complexity also introduced potential points of failure. The key is understanding where these potential weaknesses lie. The following sections will delve into the most commonly reported problems.

The Dreaded "Limp Mode" and Fuel Delivery Issues

One of the most frustrating issues reported by T660 Turbo owners is the dreaded "limp mode." This occurs when the engine's electronic control unit (ECU) detects a problem and reduces engine power to protect it from damage. Often, this is accompanied by a warning light or code on the instrument panel.

  • Causes of Limp Mode:

    • Fuel Pressure Problems: The fuel pump is a common culprit. Over time, it can degrade, leading to insufficient fuel pressure, especially under heavy load. Replacing the fuel pump is often the solution.
    • Boost Leaks: Leaks in the turbocharger system, such as a cracked hose or loose clamp, can cause a loss of boost pressure, triggering limp mode. Inspect all hoses and connections carefully.
    • Faulty Sensors: The T660 Turbo relies on several sensors to monitor engine performance. A faulty sensor, such as the mass airflow (MAF) sensor or the throttle position sensor (TPS), can send incorrect information to the ECU, leading to limp mode.
    • Overheating: While generally robust, the T660 can overheat, especially in low-snow conditions. The ECU will then trigger limp mode to prevent engine damage.

  • Troubleshooting Limp Mode:

    • Check for Error Codes: The first step is to check for error codes using a diagnostic tool. This can pinpoint the source of the problem.
    • Inspect Fuel System: Test fuel pressure to ensure the fuel pump is functioning correctly. Visually inspect the fuel lines for cracks or leaks.
    • Inspect Turbo System: Check all hoses and connections for leaks. Listen for hissing sounds when the engine is running.
    • Check Sensors: Use a multimeter to test the resistance of the MAF and TPS sensors. Consult the service manual for the correct values.
    • Cooling System: Check coolant level and inspect the radiator and heat exchangers for leaks or damage.

Turbo Troubles: Boost Leaks and Actuator Issues

The turbocharger is a critical component of the T660 Turbo, and any problems with it can significantly impact performance. Boost leaks, as mentioned earlier, are a common issue. However, other turbo-related problems can also arise.

  • Boost Leaks: As we touched on, these are often due to cracked hoses or loose clamps. These can develop over time due to heat and vibration.

  • Turbo Actuator Problems: The turbo actuator controls the wastegate, which regulates boost pressure. A faulty actuator can cause overboosting or underboosting, leading to performance problems or even engine damage. The actuator can fail due to corrosion or mechanical wear.

  • Turbocharger Failure: While less common, the turbocharger itself can fail due to bearing wear or impeller damage. This is often caused by oil starvation or foreign object damage.

  • Troubleshooting Turbo Issues:

    • Visual Inspection: Carefully inspect all hoses, clamps, and connections for leaks or damage.
    • Boost Pressure Test: Use a boost gauge to monitor boost pressure. Compare the readings to the specifications in the service manual.
    • Actuator Test: Check the actuator for proper movement. You may be able to manually actuate it to see if it moves freely.
    • Turbocharger Inspection: If you suspect turbocharger failure, have it inspected by a qualified technician. They can check for bearing wear, impeller damage, and other problems.

Exhaust System Issues: Cracking and Corrosion

The exhaust system on the T660 Turbo is subjected to high temperatures and corrosive conditions, which can lead to problems over time.

  • Exhaust Manifold Cracking: The exhaust manifold is particularly susceptible to cracking, especially around the welds. This can cause exhaust leaks, leading to reduced performance and increased noise.

  • Exhaust System Corrosion: The exhaust system can corrode due to exposure to moisture and salt. This can lead to leaks and eventually require replacement of the exhaust components.

  • Muffler Problems: The muffler can also corrode or become damaged, leading to increased noise and reduced performance.

  • Troubleshooting Exhaust Issues:

    • Visual Inspection: Carefully inspect the exhaust manifold, exhaust pipes, and muffler for cracks, leaks, or corrosion.
    • Listen for Leaks: Start the engine and listen for exhaust leaks. You may be able to feel the leaks with your hand.
    • Exhaust Gas Analysis: An exhaust gas analyzer can be used to detect exhaust leaks and identify other problems with the engine.

Electrical Gremlins: Wiring and Sensor Issues

Like any complex machine, the T660 Turbo can suffer from electrical problems.

  • Wiring Harness Issues: The wiring harness can become damaged due to chafing, corrosion, or rodent damage. This can lead to intermittent electrical problems.

  • Sensor Failures: As mentioned earlier, faulty sensors can cause a variety of problems.

  • Battery Problems: The battery can fail due to age or lack of maintenance.

  • Stator Issues: The stator generates the electricity needed to power the engine and electrical system. A faulty stator can cause starting problems or electrical problems.

  • Troubleshooting Electrical Issues:

    • Visual Inspection: Carefully inspect the wiring harness for damage.
    • Check Connections: Ensure all electrical connections are clean and secure.
    • Use a Multimeter: Use a multimeter to test the voltage and resistance of electrical components.
    • Check Battery: Test the battery voltage and condition.
    • Stator Test: Have the stator tested by a qualified technician.

Suspension Woes: Bushing and Shock Absorber Wear

While not directly engine-related, suspension issues can significantly impact the ride quality and handling of the T660 Turbo.

  • Bushing Wear: The bushings in the suspension can wear out over time, leading to sloppy handling and increased noise.

  • Shock Absorber Failure: The shock absorbers can lose their damping ability, resulting in a bouncy ride.

  • Spring Sag: The springs can sag over time, reducing ground clearance and affecting handling.

  • Troubleshooting Suspension Issues:

    • Visual Inspection: Carefully inspect the bushings, shock absorbers, and springs for wear or damage.
    • Check for Play: Check for excessive play in the suspension components.
    • Test Shock Absorbers: Bounce the suspension and observe the damping action of the shock absorbers.
    • Measure Ride Height: Measure the ride height and compare it to the specifications in the service manual.

Keeping Your T660 Turbo Happy: Preventative Maintenance is Key

Many of the problems discussed above can be prevented or minimized with proper maintenance. Here are some key preventative maintenance tasks:

  • Regular Oil Changes: Change the engine oil and filter according to the manufacturer's recommendations.
  • Air Filter Maintenance: Clean or replace the air filter regularly.
  • Fuel Filter Replacement: Replace the fuel filter regularly.
  • Coolant Flush: Flush the cooling system and replace the coolant every two years.
  • Inspect Hoses and Connections: Regularly inspect all hoses and connections for leaks or damage.
  • Grease Suspension Components: Grease the suspension components regularly.
  • Check Battery: Check the battery voltage and condition regularly.
  • Store Properly: Store the snowmobile properly during the off-season.
  • Address Issues Promptly: Don't ignore small problems. Addressing them early can prevent them from becoming major issues.

Frequently Asked Questions about Arctic Cat T660 Turbo Problems

  • Why does my T660 Turbo go into limp mode? Limp mode is a safety feature triggered by the ECU when it detects a problem, like low fuel pressure or excessive boost. Diagnostic codes can help pinpoint the cause.

  • How often should I change the oil in my T660 Turbo? Refer to your owner's manual, but generally, oil changes are recommended every 500-1000 miles, or annually, whichever comes first. Using a quality synthetic oil is recommended.

  • What causes boost leaks in the turbo system? Boost leaks are typically caused by cracked hoses or loose clamps in the turbocharger system. A thorough inspection of these components is essential.

  • My T660 Turbo is hard to start, what could be the problem? Hard starting can be due to a weak battery, faulty stator, or fuel delivery issues. Check the battery voltage and have the stator tested if necessary.

  • How can I prevent my T660 Turbo from overheating? Ensure the cooling system is clean and properly filled, and avoid running the sled in low-snow conditions. Also, check the heat exchangers for proper operation.

In Conclusion

The Arctic Cat T660 Turbo offers a unique blend of power and comfort, but it's crucial to be aware of the potential problems. By understanding these issues and performing regular maintenance, you can keep your T660 Turbo running smoothly for years to come. If you're experiencing any significant problems, don't hesitate to consult a qualified snowmobile mechanic for assistance.